Semiconductor Chip Module
One aspect includes a sensor chip module including a sensor chip and a module housing accommodating the sensor chip. The module housing defines a mounting plane of the sensor chip module. In one case, an active surface of the sensor chip is inclined with respect to the mounting plane of the sensor chip module.
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This Utility Patent Application claims priority to German Patent Application No. DE 10 2007 005 630.5 filed on Feb. 5, 2007, which is incorporated herein by reference.
BACKGROUNDEmbodiments of the invention relate to modules containing a semiconductor chip.
Semiconductor modules are known in the art whose functionality depends on the orientation of the semiconductor chip with regard to the three spatial directions. Examples thereof are, inter alia, sensors or transmitters with directional emission. These include optical sensors and transmitters and, for example, also motion sensors (e.g. acceleration sensors) which, in a manner conditional on the design and depending on the orientation of the sensor spatially, detect movements in the different spatial directions with varying response characteristics.
Sensor chips are typically incorporated into a semiconductor housing in planar fashion, the active surface of the sensor chip lying parallel to the mounting plane of the semiconductor housing on an application board. If the intention is to achieve a different orientation of the sensor chip with respect to the application board, the sensor chip module is usually mounted onto a small auxiliary printed circuit board, which is then fitted to the application board in the desired orientation (e.g. perpendicular). This is associated with a relatively high outlay in respect of mounting.
SUMMARYOne aspect of the invention provides a sensor chip module including a sensor chip and a module housing accommodating the sensor chip. The module housing defines a mounting plane of the sensor chip module. An active surface of the sensor chip is inclined with respect to the mounting plane of the sensor chip module.
According to another aspect, provision is made of a module, including a first semiconductor chip having an active surface, said semiconductor chip being accommodated in a first housing, and a second semiconductor chip accommodated in a second housing. The module furthermore has a common chip carrier, on which the first semiconductor chip and the second semiconductor chip are applied. The two housings are joined together to form a common module housing, which defines a mounting plane of the module. The chip carrier is bent in such a way that the active surface of the first semiconductor chip is inclined with respect to the mounting plane.
The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles of the invention. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
A description is given below of modules having a semiconductor chip whose active surface is inclined, i.e. does not run parallel, with respect to the mounting plane of the module. In this case, the semiconductor chip may be of a wide variety of types. By way of example, it may contain electromechanical or electro-optical functional elements in the region of its active surface. It may be realized in the form of a sensor chip or an emitter with directional emission. Examples in the optical field are photodiodes or diode lasers. A sensor chip may be embodied as a so-called MEMS (Micro-Electro-Mechanical System), i.e. microelectronic mechanical system, wherein micromechanical movable structures such as, for example, bridges, membranes or reed structures may be provided. Such sensor chips may be motion sensors, in particular, which may be embodied as acceleration sensors (which detect accelerations in different spatial directions), or rotation sensors. Sensors of this type are also referred to as gyrosensors, roll-over sensors, impact sensors, inertial sensors, etc. and are used for example in the automotive industry for signal detection in ESP (Electronic Stability Program) systems, ABS (Anti-lock Braking Systems), airbags and the like.
Semiconductor modules into which such functional elements are embedded generally include electronic circuits which serve for driving the functional elements or process further signals that are generated by the functional elements. Such electronic circuits may be implemented either on the semiconductor chip forming the functional element or on a separate semiconductor chip integrated into the module. By way of example, in the case of a motion sensor, the deflection of a movable micro-functional element may be read piezoresistively or capacitively and be processed further in such electronic circuits. The separate semiconductor chip may be embodied for example as an ASIC (Application Specific Integrated Circuit) and have e.g. an RF (Radio-Frequency) functionality for wireless signal forwarding.
A leadframe 1 of this type can be produced for example by stamping or etching from a thin metal layer (the thickness of the metal layer may be e.g. within the range of 0.1 mm to a few millimeters) of a metal strip. Leadframes, as interconnection frames, serve both as chip carriers and for realizing the leads for the external contact-connection of the sensor chip module. On account of the high reliability of modules with leads, modules produced on a leadframe basis are used to a great extent in the automotive industry.
In a next step S2, a hollow housing 2 is fitted to the leadframe 1. The hollow housing 2 is typically produced prior to the mounting of the sensor chip by plastic injection-moulding encapsulation of the leadframe 1. After the leadframe 1 has been encapsulated by injection moulding, the plastic hollow housing 2 is fixedly connected to the leadframe 1.
In a next step S3, a sensor chip 3 is inserted into the hollow housing 2, mounted onto the leadframe 1 and electrically connected to connection elements 1a of the leadframe 1. The sensor chip 3 can be mounted onto the leadframe 1 by means of adhesive bonding or soldering, by way of example. In accordance with
After the mounting and the contact-connection of the sensor chip 3 onto and to the leadframe 1, the sensor chip 3 can be potted with a soft gel (e.g. silicone gel) in the hollow housing 2 for reliability reasons (not illustrated in
A bending-over step is effected later, in the course of which the hollow housing 2 is folded over with respect to the leadframe 1 in such a way that the sensor chip 3 attains a position that is tilted with respect to the connecting elements 1a of the leadframe 1. In particular, 90° tilting may be performed, as illustrated in
The mounting of the sensor chip module onto an application board (not illustrated), e.g. a printed circuit board composed of epoxy resin or some other metallized support, is effected by means of the connection elements 1a. What is achieved owing to the preceding leadframe bending step is that, unlike in the case of a customary “horizontal” mounting of the sensor chip module onto the application board, the sensor chip is oriented in a manner inclined with respect to the plane of the application board (not illustrated). In this case, the mounting plane of the sensor chip module in
What is achieved by the bending-over of the leadframe 1 for the reorientation of the hollow housing 2 with respect to the connection elements 1a of the leadframe 1 is that during placement on an application board, the sensor chip 3 is automatically mounted in a position on the application board in which its active surface and the functional elements formed e.g. in micromechanical fashion therein do not run parallel to the mounting plane of the sensor chip module.
The starting point of the production sequence is once again a planar, unbent leadframe 1 including e.g. a plurality of sections 1a, 1b, 1c and 1d. The section 1b serves as a chip carrier for the sensor chip 3 and the section 1c serves as a chip carrier for the semiconductor chip 5. As can be seen from
The sensor chip module shown in
Firstly, the planar leadframe 1 having the abovementioned leadframe sections 1a, 1b, 1c, 1d is produced. In accordance with a first possible method sequence, the semiconductor chip 5 is mounted (e.g. adhesively bonded or soldered) onto the leadframe 1 and is electrically contact-connected thereto. The electrical contact-connection thereto may be effected e.g. by means of bonding wires 7 which connect pads 8 on the active surface of the semiconductor chip 5 to the connection elements 1a and 1d of the leadframe 1. Other mounting and contact-connection techniques, e.g. the flip-chip technique, are likewise possible.
The leadframe 1 with the semiconductor chip 5 mounted thereon and contact-connected thereto is then introduced into an injection mould having two cavities for the production of the hollow housing 2 and of the semiconductor chip housing 6. Therefore, the two housings 2 and 6 are in one example injection-moulded onto the leadframe 1 in one workstep. After the injection-moulding operation, the semiconductor chip 5 is completely housed.
As an alternative, it is also possible for the semiconductor chip 5 to be mounted onto and electrically contact-connected to the leadframe 1 only after the encapsulation of the leadframe 1 by injection moulding. In this case, the semiconductor chip housing 6 is likewise a hollow housing (comparable to the hollow housing 2) into which the semiconductor chip 5 is subsequently introduced. This embodiment variant with two housings 2, 6 having SMD (Surface Mounted Device) placement capability is explained later with reference to
Since the semiconductor chip 5 typically does not contain a sensor system but rather functions as a driver chip or evaluation chip for the sensor chip 3, the semiconductor chip 5 is generally insensitive to mechanical strains and can therefore be encapsulated with a plastic solid housing 6 by injection moulding in accordance with the first production variant.
Afterwards, as already explained with reference to
The completed sensor chip module after the bending-over step has been carried out can be discerned in the bottommost illustration in
As can be discerned in the bottommost illustration in
In a further step, the leadframe sections 1d are bent over in such a way that they form leads of the sensor chip module. The leads of the sensor chip module are utilized as external contacts for the electrical contact-connection of the sensor chip module on an application board (not illustrated). As can be gathered from
After the semiconductor chip 5 has been embedded into the potting composition 9, the hollow housing 106 is closed off by a cap 106a. The closure of the hollow housing 2 with the sensor chip 3 contained therein is once again effected by means of the bending-over step.
The housing variants illustrated in
A further aspect relates to the use of a flexible chip carrier instead of the leadframe 1, 11. A flexible chip carrier may be formed as a multilayer structure comprising at least one plastic layer (for example polyimide) and a metallization layer lying above the latter. The plastic layer may be approximately 100 μm thick, by way of example, and the thickness of the metallization layer may lie e.g. within the range of 5 to 20 μm. Structures having a plurality of metallization layers are likewise possible. Flexible chip carriers are also known by the expressions flexible substrates or flexible printed circuit boards.
The flexible chip carrier 100 has a metallization layer 101, which is applied on a plastic carrier layer 102. The metallization layer 101 is patterned in order to form conductor paths. By way of example, photolithographic methods may be used for the patterning of the metallization layer 101.
The sensor chip hollow housing 2 and the semiconductor chip housing 6 are fitted to the flexible chip carrier 100. This may be effected by injection moulding in an injection mould in the manner already described. In this case, the flexible chip carrier 100, in the injection mould, may bear on walls of the two injection-moulding cavities in such a way that it is backed by injection moulding and not encapsulated by injection moulding. As a result, the plastic carrier layer 102 remains uncovered on the rear side even in the region of the housings 2, 6.
The folding-over step for the orientation of the sensor chip housing 2 is made possible by the flexibility of the flexible chip carrier 100.
In the plastic carrier layer 102, plated-through holes 103 are provided at suitable locations, which holes are introduced, in a manner that is not illustrated, either as early as on the flexible chip carrier 100 that has not yet been backed by injection moulding, or during any desired later point in time in the production sequence (e.g. on one of the products illustrated in
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
Claims
1. A sensor chip module, comprising:
- a sensor chip; and
- a module housing accommodating the sensor chip, which module housing defines a mounting plane of the sensor chip module;
- wherein an active surface of the sensor chip is inclined with respect to the mounting plane of the sensor chip module.
2. The sensor chip module according to claim 1, further comprising a chip carrier, on which the sensor chip is applied.
3. The sensor chip module according to claim 2, wherein the chip carrier is bent in order that the active surface of the sensor chip is inclined with respect to the mounting plane of the sensor chip module.
4. The sensor chip module according to claim 2, wherein the chip carrier is a metallic leadframe carrier.
5. The sensor chip module according to claim 2, wherein the chip carrier is a flexible plastic carrier with conductors metallized thereon.
6. The sensor chip module according to claim 1, wherein the active surface of the sensor chip runs essentially perpendicular to the mounting plane of the sensor chip module.
7. The sensor chip module according to claim 1, wherein the module housing is realized as an individual sensor chip housing accommodating the sensor chip.
8. The sensor chip module according to claim 2, wherein a semiconductor chip is furthermore applied on the chip carrier.
9. The sensor chip module according to claim 8, wherein the module housing comprises a sensor chip housing accommodating the sensor chip and a semiconductor chip housing accommodating the semiconductor chip.
10. The sensor chip module according to claim 7, wherein the sensor chip housing is a hollow housing.
11. The sensor chip module according to claim 10, wherein the sensor chip hollow housing is filled with a potting composition.
12. The sensor chip module according to claim 9, wherein the semiconductor chip housing is a plastic injection-moulding housing realized by encapsulation of the semiconductor chip by injection moulding.
13. The sensor chip module according to claim 9, wherein the sensor chip housing is a hollow housing and an opening of the sensor chip hollow housing is closed off by a wall of the semiconductor chip housing.
14. The sensor chip module according to claim 2, wherein the chip carrier extends along an outer wall of the sensor chip housing.
15. The sensor chip module according to claim 14, wherein the chip carrier forms an external contact-connection section in the region of the outer wall of the sensor chip housing.
16. The sensor chip module according to claim 1, wherein the sensor chip is a motion sensor.
17. The sensor chip module according to claim 9, wherein the semiconductor chip has a signal evaluation circuit for the signal evaluation of sensor signals and/or a driver circuit for driving the sensor chip and/or a logic circuit.
18. A module, comprising:
- a first semiconductor chip having an active surface, which is accommodated in a first housing;
- a second semiconductor chip having an active surface, which is accommodated in a second housing; and
- a common chip carrier, on which the first semiconductor chip and the second semiconductor chip are applied;
- wherein the two housings are joined together to form a common module housing and the chip carrier is bent in such a way that the active surface of the first semiconductor chip is inclined with respect to the active surface of the second semiconductor chip.
19. The module according to claim 18, wherein the first semiconductor chip is a sensor chip and/or an optical chip.
20. The module according to claim 18, wherein the chip carrier is a metallic leadframe carrier.
21. The module according to claim 18, wherein the chip carrier is a flexible plastic carrier with conductors metallized thereon.
22. The module according to claim 18, wherein the second semiconductor chip has a signal evaluation circuit for the signal evaluation of signals of the first semiconductor chip and/or a driver circuit for driving the first semiconductor chip and/or a logic circuit.
23. A method for producing a sensor module, comprising:
- producing a sensor chip housing with sensor chip accommodated therein;
- applying the sensor chip on a chip carrier; and
- bending the chip carrier into a mounting plane of the sensor chip housing such that an active surface of the sensor chip is inclined with respect to the mounting plane of the sensor chip housing.
24. The method according to claim 23, wherein firstly the sensor chip housing is fitted to the chip carrier and then the sensor chip is applied to the chip carrier.
25. The method according to claim 24, wherein the sensor chip housing is potted with a potting composition after the application of the sensor chip to the chip carrier.
26. The method according to claim 23, wherein a semiconductor chip is applied to the chip carrier.
27. The method according to claim 26, wherein a semiconductor chip housing accommodating the semiconductor chip is fitted to the chip carrier.
28. The method according to claim 27, wherein, as a result of the bending of the chip carrier, an opening of the sensor chip housing is caused to bear against the wall of the semiconductor chip housing and is closed off by said wall.
29. The method according to claims 23, wherein the bending of the chip carrier is effected outside the sensor chip housing.
30. A method for producing a module, comprising:
- producing a first housing with a first semiconductor chip accommodated therein, said semiconductor chip being applied on a chip carrier;
- producing a second housing with a second semiconductor chip accommodated therein, said semiconductor chip being applied on the chip carrier, and
- bending the chip carrier in the region between the first housing and the second housing in order to join the first housing together with the second housing to form a common module housing.
31. The method according to claim 30, wherein, as a result of the bending of the chip carrier an active surface of the first semiconductor chip is inclined with respect to the mounting area of the common module housing.
Type: Application
Filed: Feb 19, 2007
Publication Date: Aug 7, 2008
Patent Grant number: 7851829
Applicant: INFINEON TECHNOLOGIES AG (Munchen)
Inventor: Horst Theuss (Wenzenbach)
Application Number: 11/676,372
International Classification: H01L 31/0203 (20060101); H01L 31/18 (20060101);